Search warrants have been executed up and down the country as part of an investigation into pokie machine grant manipulation.

Internal Affairs director of gambling compliance Debbie Despard said the investigation was significant, involving a number of agencies including the Serious Fraud Office.

No details on the amount or search warrants or their location were made public.

"The Department of Internal Affairs has responsibility to ensure the integrity of the grants system in pokie machine gambling.

"The wider community is disadvantaged if one group can gain preferential access to grant funding from gambling proceeds," Despard said.

"Where the Department finds serious, harmful, and deliberate non-compliance in the gambling sector we will hold people to account. Our ability to do this is enhanced by drawing on the specialist resources of the SFO."

NZ Community Trust confirmed it has been contacted by the Department of Internal Affairs and Serious Fraud Office over alleged manipulation of gaming funds.

The trust has issued a statement saying it does not believe it is the subject of the enquiry.

"NZ Community Trust will continue to assist both agencies with their investigation and supports any and all measures to ensure that the distribution of gaming machine funds is undertaken within the law.

"NZ Community Trust is not in a position to comment further until the DIA and the SFO complete their investigation."